Various fuel supply systems are proposed in the prior art. For instance, JP-A-H07-293397, JP-A-S62-35088, JP-A-2001-99029, JP-A-2004-137986, and others disclose a fuel supply system that supplies the fuel in the fuel tank to an internal combustion engine via an electric fuel pump. In JP-A-H07-293397, for instance, a controller electrically controls operation of the fuel pump. It is necessary to cool the controller because electronic parts mounted on the controller, such as a power transistor, generate heat.
Conventionally, the controller is equipped with a cooling fin for air cooling. More specifically, the cooling fin is provided on an external surface of a lid member of the fuel tank. Also, the cooling fin is provided between the fuel tank and a car body member. However, if the clearance between the fuel tank and the car body member is small, the cooling fin may be smaller, which disadvantageously reduces the cooling capability of the controller.
In partial response to this problem, systems have been proposed that include a cooling structure for cooling the controller with the fuel instead of via air cooling. For instance, JP-A-S62-35088 and JP-A-2001-99029 disclose this type of system.
More specifically, JP-A-S62-35088 discloses a structure in which the controller contacts the external surface of a metallic lid member, and a cooling fin is included that is capable of exchanging heat with the fuel. The cooling fin is provided on the inside of the lid member, and the cooling fin is cooled by the fuel. As such, the lid member is interposed between the controller and the cooling fin, and accordingly cooling capability may be insufficient. More specifically, if the lid member is made of a resin, the cooling capability decreases considerably because the resin has low thermal conductivity.
Furthermore, JP-A-2001-99029 discloses a structure in which a metallic cooling plate contacting the controller is provided, and the cooling plate is insert-molded with resin so as to be formed coupled to and around a resin-made fuel pipe through which the fuel circulates. Thus, the cooling plate is cooled by the circuiting fuel. As such, the resin-made fuel pipe is interposed between the circulating fuel and the cooling plate, and accordingly the cooling capability may be decreased.